text: // Copyright (c) 2020-2021 The Eleccoin Core developers
  // Distributed under the MIT software license, see the accompanying
  // file COPYING or http://www.opensource.org/licenses/mit-license.php.
  
  #include <key_io.h>
  #include <outputtype.h>
  #include <rpc/util.h>
  #include <script/descriptor.h>
  #include <script/signingprovider.h>
  #include <tinyformat.h>
  #include <util/strencodings.h>
  #include <util/string.h>
  #include <util/translation.h>
  
  #include <tuple>
  
  #include <boost/algorithm/string/classification.hpp>
  #include <boost/algorithm/string/split.hpp>
  
  const std::string UNIX_EPOCH_TIME = "UNIX epoch time";
  const std::string EXAMPLE_ADDRESS[2] = {"ec1qw7sscf84h5ge2evxcx24e9euxnqys8w5242kjx", "ec1qy8e9mvumux4y23mwgy0tnsqq99w6ctmd64qgr7"};
  
  void RPCTypeCheck(const UniValue& params,
                    const std::list<UniValueType>& typesExpected,
                    bool fAllowNull)
  {
      unsigned int i = 0;
      for (const UniValueType& t : typesExpected) {
          if (params.size() <= i)
              break;
  
          const UniValue& v = params[i];
          if (!(fAllowNull && v.isNull())) {
              RPCTypeCheckArgument(v, t);
          }
          i++;
      }
  }
  
  void RPCTypeCheckArgument(const UniValue& value, const UniValueType& typeExpected)
  {
      if (!typeExpected.typeAny && value.type() != typeExpected.type) {
          throw JSONRPCError(RPC_TYPE_ERROR, strprintf("Expected type %s, got %s", uvTypeName(typeExpected.type), uvTypeName(value.type())));
      }
  }
  
  void RPCTypeCheckObj(const UniValue& o,
      const std::map<std::string, UniValueType>& typesExpected,
      bool fAllowNull,
      bool fStrict)
  {
      for (const auto& t : typesExpected) {
          const UniValue& v = find_value(o, t.first);
          if (!fAllowNull && v.isNull())
              throw JSONRPCError(RPC_TYPE_ERROR, strprintf("Missing %s", t.first));
  
          if (!(t.second.typeAny || v.type() == t.second.type || (fAllowNull && v.isNull()))) {
              std::string err = strprintf("Expected type %s for %s, got %s",
                  uvTypeName(t.second.type), t.first, uvTypeName(v.type()));
              throw JSONRPCError(RPC_TYPE_ERROR, err);
          }
      }
  
      if (fStrict)
      {
          for (const std::string& k : o.getKeys())
          {
              if (typesExpected.count(k) == 0)
              {
                  std::string err = strprintf("Unexpected key %s", k);
                  throw JSONRPCError(RPC_TYPE_ERROR, err);
              }
          }
      }
  }
  
  CAmount AmountFromValue(const UniValue& value, int decimals)
  {
      if (!value.isNum() && !value.isStr())
          throw JSONRPCError(RPC_TYPE_ERROR, "Amount is not a number or string");
      CAmount amount;
      if (!ParseFixedPoint(value.getValStr(), decimals, &amount))
          throw JSONRPCError(RPC_TYPE_ERROR, "Invalid amount");
      if (!MoneyRange(amount))
          throw JSONRPCError(RPC_TYPE_ERROR, "Amount out of range");
      return amount;
  }
  
  uint256 ParseHashV(const UniValue& v, std::string strName)
  {
      std::string strHex(v.get_str());
      if (64 != strHex.length())
          throw JSONRPCError(RPC_INVALID_PARAMETER, strprintf("%s must be of length %d (not %d, for '%s')", strName, 64, strHex.length(), strHex));
      if (!IsHex(strHex)) // Note: IsHex("") is false
          throw JSONRPCError(RPC_INVALID_PARAMETER, strName+" must be hexadecimal string (not '"+strHex+"')");
      return uint256S(strHex);
  }
  uint256 ParseHashO(const UniValue& o, std::string strKey)
  {
      return ParseHashV(find_value(o, strKey), strKey);
  }
  std::vector<unsigned char> ParseHexV(const UniValue& v, std::string strName)
  {
      std::string strHex;
      if (v.isStr())
          strHex = v.get_str();
      if (!IsHex(strHex))
          throw JSONRPCError(RPC_INVALID_PARAMETER, strName+" must be hexadecimal string (not '"+strHex+"')");
      return ParseHex(strHex);
  }
  std::vector<unsigned char> ParseHexO(const UniValue& o, std::string strKey)
  {
      return ParseHexV(find_value(o, strKey), strKey);
  }
  
  namespace {
  
  /**
   * Quote an argument for shell.
   *
   * @note This is intended for help, not for security-sensitive purposes.
   */
  std::string ShellQuote(const std::string& s)
  {
      std::string result;
      result.reserve(s.size() * 2);
      for (const char ch: s) {
          if (ch == '\'') {
              result += "'\''";
          } else {
              result += ch;
          }
      }
      return "'" + result + "'";
  }
  
  /**
   * Shell-quotes the argument if it needs quoting, else returns it literally, to save typing.
   *
   * @note This is intended for help, not for security-sensitive purposes.
   */
  std::string ShellQuoteIfNeeded(const std::string& s)
  {
      for (const char ch: s) {
          if (ch == ' ' || ch == '\'' || ch == '"') {
              return ShellQuote(s);
          }
      }
  
      return s;
  }
  
  }
  
  std::string HelpExampleCli(const std::string& methodname, const std::string& args)
  {
      return "> eleccoin-cli " + methodname + " " + args + "\n";
  }
  
  std::string HelpExampleCliNamed(const std::string& methodname, const RPCArgList& args)
  {
      std::string result = "> eleccoin-cli -named " + methodname;
      for (const auto& argpair: args) {
          const auto& value = argpair.second.isStr()
                  ? argpair.second.get_str()
                  : argpair.second.write();
          result += " " + argpair.first + "=" + ShellQuoteIfNeeded(value);
      }
      result += "\n";
      return result;
  }
  
  std::string HelpExampleRpc(const std::string& methodname, const std::string& args)
  {
      return "> curl --user myusername --data-binary '{\"jsonrpc\": \"1.0\", \"id\": \"curltest\", "
          "\"method\": \"" + methodname + "\", \"params\": [" + args + "]}' -H 'content-type: text/plain;' http://127.0.0.1:9832/\n";
  }
  
  std::string HelpExampleRpcNamed(const std::string& methodname, const RPCArgList& args)
  {
      UniValue params(UniValue::VOBJ);
      for (const auto& param: args) {
          params.pushKV(param.first, param.second);
      }
  
      return "> curl --user myusername --data-binary '{\"jsonrpc\": \"1.0\", \"id\": \"curltest\", "
             "\"method\": \"" + methodname + "\", \"params\": " + params.write() + "}' -H 'content-type: text/plain;' http://127.0.0.1:9832/\n";
  }
  
  // Converts a hex string to a public key if possible
  CPubKey HexToPubKey(const std::string& hex_in)
  {
      if (!IsHex(hex_in)) {
          throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Invalid public key: " + hex_in);
      }
      CPubKey vchPubKey(ParseHex(hex_in));
      if (!vchPubKey.IsFullyValid()) {
          throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Invalid public key: " + hex_in);
      }
      return vchPubKey;
  }
  
  // Retrieves a public key for an address from the given FillableSigningProvider
  CPubKey AddrToPubKey(const FillableSigningProvider& keystore, const std::string& addr_in)
  {
      CTxDestination dest = DecodeDestination(addr_in);
      if (!IsValidDestination(dest)) {
          throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, "Invalid address: " + addr_in);
      }
      CKeyID key = GetKeyForDestination(keystore, dest);
      if (key.IsNull()) {
          throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, strprintf("%s does not refer to a key", addr_in));
      }
      CPubKey vchPubKey;
      if (!keystore.GetPubKey(key, vchPubKey)) {
          throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, strprintf("no full public key for address %s", addr_in));
      }
      if (!vchPubKey.IsFullyValid()) {
         throw JSONRPCError(RPC_INTERNAL_ERROR, "Wallet contains an invalid public key");
      }
      return vchPubKey;
  }
  
  // Creates a multisig address from a given list of public keys, number of signatures required, and the address type
  CTxDestination AddAndGetMultisigDestination(const int required, const std::vector<CPubKey>& pubkeys, OutputType type, FillableSigningProvider& keystore, CScript& script_out)
  {
      // Gather public keys
      if (required < 1) {
          throw JSONRPCError(RPC_INVALID_PARAMETER, "a multisignature address must require at least one key to redeem");
      }
      if ((int)pubkeys.size() < required) {
          throw JSONRPCError(RPC_INVALID_PARAMETER, strprintf("not enough keys supplied (got %u keys, but need at least %d to redeem)", pubkeys.size(), required));
      }
      if (pubkeys.size() > MAX_PUBKEYS_PER_MULTISIG) {
          throw JSONRPCError(RPC_INVALID_PARAMETER, strprintf("Number of keys involved in the multisignature address creation > %d\nReduce the number", MAX_PUBKEYS_PER_MULTISIG));
      }
  
      script_out = GetScriptForMultisig(required, pubkeys);
  
      // Check if any keys are uncompressed. If so, the type is legacy
      for (const CPubKey& pk : pubkeys) {
          if (!pk.IsCompressed()) {
              type = OutputType::LEGACY;
              break;
          }
      }
  
      if (type == OutputType::LEGACY && script_out.size() > MAX_SCRIPT_ELEMENT_SIZE) {
          throw JSONRPCError(RPC_INVALID_PARAMETER, (strprintf("redeemScript exceeds size limit: %d > %d", script_out.size(), MAX_SCRIPT_ELEMENT_SIZE)));
      }
  
      // Make the address
      CTxDestination dest = AddAndGetDestinationForScript(keystore, script_out, type);
  
      return dest;
  }
  
  class DescribeAddressVisitor
  {
  public:
      explicit DescribeAddressVisitor() {}
  
      UniValue operator()(const CNoDestination& dest) const
      {
          return UniValue(UniValue::VOBJ);
      }
  
      UniValue operator()(const PKHash& keyID) const
      {
          UniValue obj(UniValue::VOBJ);
          obj.pushKV("isscript", false);
          obj.pushKV("iswitness", false);
          return obj;
      }
  
      UniValue operator()(const ScriptHash& scriptID) const
      {
          UniValue obj(UniValue::VOBJ);
          obj.pushKV("isscript", true);
          obj.pushKV("iswitness", false);
          return obj;
      }
  
      UniValue operator()(const WitnessV0KeyHash& id) const
      {
          UniValue obj(UniValue::VOBJ);
          obj.pushKV("isscript", false);
          obj.pushKV("iswitness", true);
          obj.pushKV("witness_version", 0);
          obj.pushKV("witness_program", HexStr(id));
          return obj;
      }
  
      UniValue operator()(const WitnessV0ScriptHash& id) const
      {
          UniValue obj(UniValue::VOBJ);
          obj.pushKV("isscript", true);
          obj.pushKV("iswitness", true);
          obj.pushKV("witness_version", 0);
          obj.pushKV("witness_program", HexStr(id));
          return obj;
      }
  
      UniValue operator()(const WitnessV1Taproot& tap) const
      {
          UniValue obj(UniValue::VOBJ);
          obj.pushKV("isscript", true);
          obj.pushKV("iswitness", true);
          obj.pushKV("witness_version", 1);
          obj.pushKV("witness_program", HexStr(tap));
          return obj;
      }
  
      UniValue operator()(const WitnessUnknown& id) const
      {
          UniValue obj(UniValue::VOBJ);
          obj.pushKV("iswitness", true);
          obj.pushKV("witness_version", (int)id.version);
          obj.pushKV("witness_program", HexStr(Span<const unsigned char>(id.program, id.length)));
          return obj;
      }
  };
  
  UniValue DescribeAddress(const CTxDestination& dest)
  {
      return std::visit(DescribeAddressVisitor(), dest);
  }
  
  unsigned int ParseConfirmTarget(const UniValue& value, unsigned int max_target)
  {
      const int target{value.get_int()};
      const unsigned int unsigned_target{static_cast<unsigned int>(target)};
      if (target < 1 || unsigned_target > max_target) {
          throw JSONRPCError(RPC_INVALID_PARAMETER, strprintf("Invalid conf_target, must be between %u and %u", 1, max_target));
      }
      return unsigned_target;
  }
  
  RPCErrorCode RPCErrorFromTransactionError(TransactionError terr)
  {
      switch (terr) {
          case TransactionError::MEMPOOL_REJECTED:
              return RPC_TRANSACTION_REJECTED;
          case TransactionError::ALREADY_IN_CHAIN:
              return RPC_TRANSACTION_ALREADY_IN_CHAIN;
          case TransactionError::P2P_DISABLED:
              return RPC_CLIENT_P2P_DISABLED;
          case TransactionError::INVALID_PSBT:
          case TransactionError::PSBT_MISMATCH:
              return RPC_INVALID_PARAMETER;
          case TransactionError::SIGHASH_MISMATCH:
              return RPC_DESERIALIZATION_ERROR;
          default: break;
      }
      return RPC_TRANSACTION_ERROR;
  }
  
  UniValue JSONRPCTransactionError(TransactionError terr, const std::string& err_string)
  {
      if (err_string.length() > 0) {
          return JSONRPCError(RPCErrorFromTransactionError(terr), err_string);
      } else {
          return JSONRPCError(RPCErrorFromTransactionError(terr), TransactionErrorString(terr).original);
      }
  }
  
  /**
   * A pair of strings that can be aligned (through padding) with other Sections
   * later on
   */
  struct Section {
      Section(const std::string& left, const std::string& right)
          : m_left{left}, m_right{right} {}
      std::string m_left;
      const std::string m_right;
  };
  
  /**
   * Keeps track of RPCArgs by transforming them into sections for the purpose
   * of serializing everything to a single string
   */
  struct Sections {
      std::vector<Section> m_sections;
      size_t m_max_pad{0};
  
      void PushSection(const Section& s)
      {
          m_max_pad = std::max(m_max_pad, s.m_left.size());
          m_sections.push_back(s);
      }
  
      /**
       * Recursive helper to translate an RPCArg into sections
       */
      void Push(const RPCArg& arg, const size_t current_indent = 5, const OuterType outer_type = OuterType::NONE)
      {
          const auto indent = std::string(current_indent, ' ');
          const auto indent_next = std::string(current_indent + 2, ' ');
          const bool push_name{outer_type == OuterType::OBJ}; // Dictionary keys must have a name
  
          switch (arg.m_type) {
          case RPCArg::Type::STR_HEX:
          case RPCArg::Type::STR:
          case RPCArg::Type::NUM:
          case RPCArg::Type::AMOUNT:
          case RPCArg::Type::RANGE:
          case RPCArg::Type::BOOL: {
              if (outer_type == OuterType::NONE) return; // Nothing more to do for non-recursive types on first recursion
              auto left = indent;
              if (arg.m_type_str.size() != 0 && push_name) {
                  left += "\"" + arg.GetName() + "\": " + arg.m_type_str.at(0);
              } else {
                  left += push_name ? arg.ToStringObj(/* oneline */ false) : arg.ToString(/* oneline */ false);
              }
              left += ",";
              PushSection({left, arg.ToDescriptionString()});
              break;
          }
          case RPCArg::Type::OBJ:
          case RPCArg::Type::OBJ_USER_KEYS: {
              const auto right = outer_type == OuterType::NONE ? "" : arg.ToDescriptionString();
              PushSection({indent + (push_name ? "\"" + arg.GetName() + "\": " : "") + "{", right});
              for (const auto& arg_inner : arg.m_inner) {
                  Push(arg_inner, current_indent + 2, OuterType::OBJ);
              }
              if (arg.m_type != RPCArg::Type::OBJ) {
                  PushSection({indent_next + "...", ""});
              }
              PushSection({indent + "}" + (outer_type != OuterType::NONE ? "," : ""), ""});
              break;
          }
          case RPCArg::Type::ARR: {
              auto left = indent;
              left += push_name ? "\"" + arg.GetName() + "\": " : "";
              left += "[";
              const auto right = outer_type == OuterType::NONE ? "" : arg.ToDescriptionString();
              PushSection({left, right});
              for (const auto& arg_inner : arg.m_inner) {
                  Push(arg_inner, current_indent + 2, OuterType::ARR);
              }
              PushSection({indent_next + "...", ""});
              PushSection({indent + "]" + (outer_type != OuterType::NONE ? "," : ""), ""});
              break;
          }
          } // no default case, so the compiler can warn about missing cases
      }
  
      /**
       * Concatenate all sections with proper padding
       */
      std::string ToString() const
      {
          std::string ret;
          const size_t pad = m_max_pad + 4;
          for (const auto& s : m_sections) {
              // The left part of a section is assumed to be a single line, usually it is the name of the JSON struct or a
              // brace like {, }, [, or ]
              CHECK_NONFATAL(s.m_left.find('\n') == std::string::npos);
              if (s.m_right.empty()) {
                  ret += s.m_left;
                  ret += "\n";
                  continue;
              }
  
              std::string left = s.m_left;
              left.resize(pad, ' ');
              ret += left;
  
              // Properly pad after newlines
              std::string right;
              size_t begin = 0;
              size_t new_line_pos = s.m_right.find_first_of('\n');
              while (true) {
                  right += s.m_right.substr(begin, new_line_pos - begin);
                  if (new_line_pos == std::string::npos) {
                      break; //No new line
                  }
                  right += "\n" + std::string(pad, ' ');
                  begin = s.m_right.find_first_not_of(' ', new_line_pos + 1);
                  if (begin == std::string::npos) {
                      break; // Empty line
                  }
                  new_line_pos = s.m_right.find_first_of('\n', begin + 1);
              }
              ret += right;
              ret += "\n";
          }
          return ret;
      }
  };
  
  RPCHelpMan::RPCHelpMan(std::string name, std::string description, std::vector<RPCArg> args, RPCResults results, RPCExamples examples)
      : RPCHelpMan{std::move(name), std::move(description), std::move(args), std::move(results), std::move(examples), nullptr} {}
  
  RPCHelpMan::RPCHelpMan(std::string name, std::string description, std::vector<RPCArg> args, RPCResults results, RPCExamples examples, RPCMethodImpl fun)
      : m_name{std::move(name)},
        m_fun{std::move(fun)},
        m_description{std::move(description)},
        m_args{std::move(args)},
        m_results{std::move(results)},
        m_examples{std::move(examples)}
  {
      std::set<std::string> named_args;
      for (const auto& arg : m_args) {
          std::vector<std::string> names;
          boost::split(names, arg.m_names, boost::is_any_of("|"));
          // Should have unique named arguments
          for (const std::string& name : names) {
              CHECK_NONFATAL(named_args.insert(name).second);
          }
          // Default value type should match argument type only when defined
          if (arg.m_fallback.index() == 2) {
              const RPCArg::Type type = arg.m_type;
              switch (std::get<RPCArg::Default>(arg.m_fallback).getType()) {
              case UniValue::VOBJ:
                  CHECK_NONFATAL(type == RPCArg::Type::OBJ);
                  break;
              case UniValue::VARR:
                  CHECK_NONFATAL(type == RPCArg::Type::ARR);
                  break;
              case UniValue::VSTR:
                  CHECK_NONFATAL(type == RPCArg::Type::STR || type == RPCArg::Type::STR_HEX || type == RPCArg::Type::AMOUNT);
                  break;
              case UniValue::VNUM:
                  CHECK_NONFATAL(type == RPCArg::Type::NUM || type == RPCArg::Type::AMOUNT || type == RPCArg::Type::RANGE);
                  break;
              case UniValue::VBOOL:
                  CHECK_NONFATAL(type == RPCArg::Type::BOOL);
                  break;
              case UniValue::VNULL:
                  // Null values are accepted in all arguments
                  break;
              default:
                  CHECK_NONFATAL(false);
                  break;
              }
          }
      }
  }
  
  std::string RPCResults::ToDescriptionString() const
  {
      std::string result;
      for (const auto& r : m_results) {
          if (r.m_type == RPCResult::Type::ANY) continue; // for testing only
          if (r.m_cond.empty()) {
              result += "\nResult:\n";
          } else {
              result += "\nResult (" + r.m_cond + "):\n";
          }
          Sections sections;
          r.ToSections(sections);
          result += sections.ToString();
      }
      return result;
  }
  
  std::string RPCExamples::ToDescriptionString() const
  {
      return m_examples.empty() ? m_examples : "\nExamples:\n" + m_examples;
  }
  
  UniValue RPCHelpMan::HandleRequest(const JSONRPCRequest& request) const
  {
      if (request.mode == JSONRPCRequest::GET_ARGS) {
          return GetArgMap();
      }
      /*
       * Check if the given request is valid according to this command or if
       * the user is asking for help information, and throw help when appropriate.
       */
      if (request.mode == JSONRPCRequest::GET_HELP || !IsValidNumArgs(request.params.size())) {
          throw std::runtime_error(ToString());
      }
      const UniValue ret = m_fun(*this, request);
      CHECK_NONFATAL(std::any_of(m_results.m_results.begin(), m_results.m_results.end(), [ret](const RPCResult& res) { return res.MatchesType(ret); }));
      return ret;
  }
  
  bool RPCHelpMan::IsValidNumArgs(size_t num_args) const
  {
      size_t num_required_args = 0;
      for (size_t n = m_args.size(); n > 0; --n) {
          if (!m_args.at(n - 1).IsOptional()) {
              num_required_args = n;
              break;
          }
      }
      return num_required_args <= num_args && num_args <= m_args.size();
  }
  
  std::vector<std::string> RPCHelpMan::GetArgNames() const
  {
      std::vector<std::string> ret;
      for (const auto& arg : m_args) {
          ret.emplace_back(arg.m_names);
      }
      return ret;
  }
  
  std::string RPCHelpMan::ToString() const
  {
      std::string ret;
  
      // Oneline summary
      ret += m_name;
      bool was_optional{false};
      for (const auto& arg : m_args) {
          if (arg.m_hidden) break; // Any arg that follows is also hidden
          const bool optional = arg.IsOptional();
          ret += " ";
          if (optional) {
              if (!was_optional) ret += "( ";
              was_optional = true;
          } else {
              if (was_optional) ret += ") ";
              was_optional = false;
          }
          ret += arg.ToString(/* oneline */ true);
      }
      if (was_optional) ret += " )";
      ret += "\n";
  
      // Description
      ret += m_description;
  
      // Arguments
      Sections sections;
      for (size_t i{0}; i < m_args.size(); ++i) {
          const auto& arg = m_args.at(i);
          if (arg.m_hidden) break; // Any arg that follows is also hidden
  
          if (i == 0) ret += "\nArguments:\n";
  
          // Push named argument name and description
          sections.m_sections.emplace_back(::ToString(i + 1) + ". " + arg.GetFirstName(), arg.ToDescriptionString());
          sections.m_max_pad = std::max(sections.m_max_pad, sections.m_sections.back().m_left.size());
  
          // Recursively push nested args
          sections.Push(arg);
      }
      ret += sections.ToString();
  
      // Result
      ret += m_results.ToDescriptionString();
  
      // Examples
      ret += m_examples.ToDescriptionString();
  
      return ret;
  }
  
  UniValue RPCHelpMan::GetArgMap() const
  {
      UniValue arr{UniValue::VARR};
      for (int i{0}; i < int(m_args.size()); ++i) {
          const auto& arg = m_args.at(i);
          std::vector<std::string> arg_names;
          boost::split(arg_names, arg.m_names, boost::is_any_of("|"));
          for (const auto& arg_name : arg_names) {
              UniValue map{UniValue::VARR};
              map.push_back(m_name);
              map.push_back(i);
              map.push_back(arg_name);
              map.push_back(arg.m_type == RPCArg::Type::STR ||
                            arg.m_type == RPCArg::Type::STR_HEX);
              arr.push_back(map);
          }
      }
      return arr;
  }
  
  std::string RPCArg::GetFirstName() const
  {
      return m_names.substr(0, m_names.find("|"));
  }
  
  std::string RPCArg::GetName() const
  {
      CHECK_NONFATAL(std::string::npos == m_names.find("|"));
      return m_names;
  }
  
  bool RPCArg::IsOptional() const
  {
      if (m_fallback.index() != 0) {
          return true;
      } else {
          return RPCArg::Optional::NO != std::get<RPCArg::Optional>(m_fallback);
      }
  }
  
  std::string RPCArg::ToDescriptionString() const
  {
      std::string ret;
      ret += "(";
      if (m_type_str.size() != 0) {
          ret += m_type_str.at(1);
      } else {
          switch (m_type) {
          case Type::STR_HEX:
          case Type::STR: {
              ret += "string";
              break;
          }
          case Type::NUM: {
              ret += "numeric";
              break;
          }
          case Type::AMOUNT: {
              ret += "numeric or string";
              break;
          }
          case Type::RANGE: {
              ret += "numeric or array";
              break;
          }
          case Type::BOOL: {
              ret += "boolean";
              break;
          }
          case Type::OBJ:
          case Type::OBJ_USER_KEYS: {
              ret += "json object";
              break;
          }
          case Type::ARR: {
              ret += "json array";
              break;
          }
          } // no default case, so the compiler can warn about missing cases
      }
      if (m_fallback.index() == 1) {
          ret += ", optional, default=" + std::get<RPCArg::DefaultHint>(m_fallback);
      } else if (m_fallback.index() == 2) {
          ret += ", optional, default=" + std::get<RPCArg::Default>(m_fallback).write();
      } else {
          switch (std::get<RPCArg::Optional>(m_fallback)) {
          case RPCArg::Optional::OMITTED: {
              // nothing to do. Element is treated as if not present and has no default value
              break;
          }
          case RPCArg::Optional::OMITTED_NAMED_ARG: {
              ret += ", optional"; // Default value is "null"
              break;
          }
          case RPCArg::Optional::NO: {
              ret += ", required";
              break;
          }
          } // no default case, so the compiler can warn about missing cases
      }
      ret += ")";
      ret += m_description.empty() ? "" : " " + m_description;
      return ret;
  }
  
  void RPCResult::ToSections(Sections& sections, const OuterType outer_type, const int current_indent) const
  {
      // Indentation
      const std::string indent(current_indent, ' ');
      const std::string indent_next(current_indent + 2, ' ');
  
      // Elements in a JSON structure (dictionary or array) are separated by a comma
      const std::string maybe_separator{outer_type != OuterType::NONE ? "," : ""};
  
      // The key name if recursed into an dictionary
      const std::string maybe_key{
          outer_type == OuterType::OBJ ?
              "\"" + this->m_key_name + "\" : " :
              ""};
  
      // Format description with type
      const auto Description = [&](const std::string& type) {
          return "(" + type + (this->m_optional ? ", optional" : "") + ")" +
                 (this->m_description.empty() ? "" : " " + this->m_description);
      };
  
      switch (m_type) {
      case Type::ELISION: {
          // If the inner result is empty, use three dots for elision
          sections.PushSection({indent + "..." + maybe_separator, m_description});
          return;
      }
      case Type::ANY: {
          CHECK_NONFATAL(false); // Only for testing
      }
      case Type::NONE: {
          sections.PushSection({indent + "null" + maybe_separator, Description("json null")});
          return;
      }
      case Type::STR: {
          sections.PushSection({indent + maybe_key + "\"str\"" + maybe_separator, Description("string")});
          return;
      }
      case Type::STR_AMOUNT: {
          sections.PushSection({indent + maybe_key + "n" + maybe_separator, Description("numeric")});
          return;
      }
      case Type::STR_HEX: {
          sections.PushSection({indent + maybe_key + "\"hex\"" + maybe_separator, Description("string")});
          return;
      }
      case Type::NUM: {
          sections.PushSection({indent + maybe_key + "n" + maybe_separator, Description("numeric")});
          return;
      }
      case Type::NUM_TIME: {
          sections.PushSection({indent + maybe_key + "xxx" + maybe_separator, Description("numeric")});
          return;
      }
      case Type::BOOL: {
          sections.PushSection({indent + maybe_key + "true|false" + maybe_separator, Description("boolean")});
          return;
      }
      case Type::ARR_FIXED:
      case Type::ARR: {
          sections.PushSection({indent + maybe_key + "[", Description("json array")});
          for (const auto& i : m_inner) {
              i.ToSections(sections, OuterType::ARR, current_indent + 2);
          }
          CHECK_NONFATAL(!m_inner.empty());
          if (m_type == Type::ARR && m_inner.back().m_type != Type::ELISION) {
              sections.PushSection({indent_next + "...", ""});
          } else {
              // Remove final comma, which would be invalid JSON
              sections.m_sections.back().m_left.pop_back();
          }
          sections.PushSection({indent + "]" + maybe_separator, ""});
          return;
      }
      case Type::OBJ_DYN:
      case Type::OBJ: {
          sections.PushSection({indent + maybe_key + "{", Description("json object")});
          for (const auto& i : m_inner) {
              i.ToSections(sections, OuterType::OBJ, current_indent + 2);
          }
          CHECK_NONFATAL(!m_inner.empty());
          if (m_type == Type::OBJ_DYN && m_inner.back().m_type != Type::ELISION) {
              // If the dictionary keys are dynamic, use three dots for continuation
              sections.PushSection({indent_next + "...", ""});
          } else {
              // Remove final comma, which would be invalid JSON
              sections.m_sections.back().m_left.pop_back();
          }
          sections.PushSection({indent + "}" + maybe_separator, ""});
          return;
      }
      } // no default case, so the compiler can warn about missing cases
      CHECK_NONFATAL(false);
  }
  
  bool RPCResult::MatchesType(const UniValue& result) const
  {
      switch (m_type) {
      case Type::ELISION: {
          return false;
      }
      case Type::ANY: {
          return true;
      }
      case Type::NONE: {
          return UniValue::VNULL == result.getType();
      }
      case Type::STR:
      case Type::STR_HEX: {
          return UniValue::VSTR == result.getType();
      }
      case Type::NUM:
      case Type::STR_AMOUNT:
      case Type::NUM_TIME: {
          return UniValue::VNUM == result.getType();
      }
      case Type::BOOL: {
          return UniValue::VBOOL == result.getType();
      }
      case Type::ARR_FIXED:
      case Type::ARR: {
          return UniValue::VARR == result.getType();
      }
      case Type::OBJ_DYN:
      case Type::OBJ: {
          return UniValue::VOBJ == result.getType();
      }
      } // no default case, so the compiler can warn about missing cases
      CHECK_NONFATAL(false);
  }
  
  std::string RPCArg::ToStringObj(const bool oneline) const
  {
      std::string res;
      res += "\"";
      res += GetFirstName();
      if (oneline) {
          res += "\":";
      } else {
          res += "\": ";
      }
      switch (m_type) {
      case Type::STR:
          return res + "\"str\"";
      case Type::STR_HEX:
          return res + "\"hex\"";
      case Type::NUM:
          return res + "n";
      case Type::RANGE:
          return res + "n or [n,n]";
      case Type::AMOUNT:
          return res + "amount";
      case Type::BOOL:
          return res + "bool";
      case Type::ARR:
          res += "[";
          for (const auto& i : m_inner) {
              res += i.ToString(oneline) + ",";
          }
          return res + "...]";
      case Type::OBJ:
      case Type::OBJ_USER_KEYS:
          // Currently unused, so avoid writing dead code
          CHECK_NONFATAL(false);
      } // no default case, so the compiler can warn about missing cases
      CHECK_NONFATAL(false);
  }
  
  std::string RPCArg::ToString(const bool oneline) const
  {
      if (oneline && !m_oneline_description.empty()) return m_oneline_description;
  
      switch (m_type) {
      case Type::STR_HEX:
      case Type::STR: {
          return "\"" + GetFirstName() + "\"";
      }
      case Type::NUM:
      case Type::RANGE:
      case Type::AMOUNT:
      case Type::BOOL: {
          return GetFirstName();
      }
      case Type::OBJ:
      case Type::OBJ_USER_KEYS: {
          const std::string res = Join(m_inner, ",", [&](const RPCArg& i) { return i.ToStringObj(oneline); });
          if (m_type == Type::OBJ) {
              return "{" + res + "}";
          } else {
              return "{" + res + ",...}";
          }
      }
      case Type::ARR: {
          std::string res;
          for (const auto& i : m_inner) {
              res += i.ToString(oneline) + ",";
          }
          return "[" + res + "...]";
      }
      } // no default case, so the compiler can warn about missing cases
      CHECK_NONFATAL(false);
  }
  
  static std::pair<int64_t, int64_t> ParseRange(const UniValue& value)
  {
      if (value.isNum()) {
          return {0, value.get_int64()};
      }
      if (value.isArray() && value.size() == 2 && value[0].isNum() && value[1].isNum()) {
          int64_t low = value[0].get_int64();
          int64_t high = value[1].get_int64();
          if (low > high) throw JSONRPCError(RPC_INVALID_PARAMETER, "Range specified as [begin,end] must not have begin after end");
          return {low, high};
      }
      throw JSONRPCError(RPC_INVALID_PARAMETER, "Range must be specified as end or as [begin,end]");
  }
  
  std::pair<int64_t, int64_t> ParseDescriptorRange(const UniValue& value)
  {
      int64_t low, high;
      std::tie(low, high) = ParseRange(value);
      if (low < 0) {
          throw JSONRPCError(RPC_INVALID_PARAMETER, "Range should be greater or equal than 0");
      }
      if ((high >> 31) != 0) {
          throw JSONRPCError(RPC_INVALID_PARAMETER, "End of range is too high");
      }
      if (high >= low + 1000000) {
          throw JSONRPCError(RPC_INVALID_PARAMETER, "Range is too large");
      }
      return {low, high};
  }
  
  std::vector<CScript> EvalDescriptorStringOrObject(const UniValue& scanobject, FlatSigningProvider& provider)
  {
      std::string desc_str;
      std::pair<int64_t, int64_t> range = {0, 1000};
      if (scanobject.isStr()) {
          desc_str = scanobject.get_str();
      } else if (scanobject.isObject()) {
          UniValue desc_uni = find_value(scanobject, "desc");
          if (desc_uni.isNull()) throw JSONRPCError(RPC_INVALID_PARAMETER, "Descriptor needs to be provided in scan object");
          desc_str = desc_uni.get_str();
          UniValue range_uni = find_value(scanobject, "range");
          if (!range_uni.isNull()) {
              range = ParseDescriptorRange(range_uni);
          }
      } else {
          throw JSONRPCError(RPC_INVALID_PARAMETER, "Scan object needs to be either a string or an object");
      }
  
      std::string error;
      auto desc = Parse(desc_str, provider, error);
      if (!desc) {
          throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, error);
      }
      if (!desc->IsRange()) {
          range.first = 0;
          range.second = 0;
      }
      std::vector<CScript> ret;
      for (int i = range.first; i <= range.second; ++i) {
          std::vector<CScript> scripts;
          if (!desc->Expand(i, provider, scripts, provider)) {
              throw JSONRPCError(RPC_INVALID_ADDRESS_OR_KEY, strprintf("Cannot derive script without private keys: '%s'", desc_str));
          }
          std::move(scripts.begin(), scripts.end(), std::back_inserter(ret));
      }
      return ret;
  }
  
  UniValue GetServicesNames(ServiceFlags services)
  {
      UniValue servicesNames(UniValue::VARR);
  
      for (const auto& flag : serviceFlagsToStr(services)) {
          servicesNames.push_back(flag);
      }
  
      return servicesNames;
  }
  